Commit 97950c3d authored by Hans de Goede's avatar Hans de Goede Committed by Jean Delvare
Browse files

hwmon: (fschmd) Add watchdog support



This patch adds support for the watchdog part found in _all_ supported FSC
sensor chips.
Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
parent 453e308d
......@@ -329,10 +329,11 @@ config SENSORS_FSCHMD
depends on X86 && I2C && EXPERIMENTAL
help
If you say yes here you get support for various Fujitsu Siemens
Computers sensor chips.
Computers sensor chips, including support for the integrated
watchdog.
This is a new merged driver for FSC sensor chips which is intended
as a replacment for the fscpos, fscscy and fscher drivers and adds
as a replacement for the fscpos, fscscy and fscher drivers and adds
support for several other FCS sensor chips.
This driver can also be built as a module. If so, the module
......
......@@ -42,11 +42,20 @@
#include <linux/mutex.h>
#include <linux/sysfs.h>
#include <linux/dmi.h>
#include <linux/fs.h>
#include <linux/watchdog.h>
#include <linux/miscdevice.h>
#include <linux/uaccess.h>
#include <linux/kref.h>
/* Addresses to scan */
static const unsigned short normal_i2c[] = { 0x73, I2C_CLIENT_END };
/* Insmod parameters */
static int nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
I2C_CLIENT_INSMOD_5(fscpos, fscher, fscscy, fschrc, fschmd);
/*
......@@ -65,11 +74,18 @@ I2C_CLIENT_INSMOD_5(fscpos, fscher, fscscy, fschrc, fschmd);
#define FSCHMD_CONTROL_ALERT_LED 0x01
/* watchdog (support to be implemented) */
/* watchdog */
#define FSCHMD_REG_WDOG_PRESET 0x28
#define FSCHMD_REG_WDOG_STATE 0x23
#define FSCHMD_REG_WDOG_CONTROL 0x21
#define FSCHMD_WDOG_CONTROL_TRIGGER 0x10
#define FSCHMD_WDOG_CONTROL_STARTED 0x10 /* the same as trigger */
#define FSCHMD_WDOG_CONTROL_STOP 0x20
#define FSCHMD_WDOG_CONTROL_RESOLUTION 0x40
#define FSCHMD_WDOG_STATE_CARDRESET 0x02
/* voltages, weird order is to keep the same order as the old drivers */
static const u8 FSCHMD_REG_VOLT[3] = { 0x45, 0x42, 0x48 };
......@@ -206,14 +222,26 @@ static struct i2c_driver fschmd_driver = {
*/
struct fschmd_data {
struct i2c_client *client;
struct device *hwmon_dev;
struct mutex update_lock;
struct mutex watchdog_lock;
struct list_head list; /* member of the watchdog_data_list */
struct kref kref;
struct miscdevice watchdog_miscdev;
int kind;
unsigned long watchdog_is_open;
char watchdog_expect_close;
char watchdog_name[10]; /* must be unique to avoid sysfs conflict */
char valid; /* zero until following fields are valid */
unsigned long last_updated; /* in jiffies */
/* register values */
u8 revision; /* chip revision */
u8 global_control; /* global control register */
u8 watchdog_control; /* watchdog control register */
u8 watchdog_state; /* watchdog status register */
u8 watchdog_preset; /* watchdog counter preset on trigger val */
u8 volt[3]; /* 12, 5, battery voltage */
u8 temp_act[5]; /* temperature */
u8 temp_status[5]; /* status of sensor */
......@@ -225,11 +253,28 @@ struct fschmd_data {
};
/* Global variables to hold information read from special DMI tables, which are
available on FSC machines with an fscher or later chip. */
available on FSC machines with an fscher or later chip. There is no need to
protect these with a lock as they are only modified from our attach function
which always gets called with the i2c-core lock held and never accessed
before the attach function is done with them. */
static int dmi_mult[3] = { 490, 200, 100 };
static int dmi_offset[3] = { 0, 0, 0 };
static int dmi_vref = -1;
/* Somewhat ugly :( global data pointer list with all fschmd devices, so that
we can find our device data as when using misc_register there is no other
method to get to ones device data from the open fop. */
static LIST_HEAD(watchdog_data_list);
/* Note this lock not only protect list access, but also data.kref access */
static DEFINE_MUTEX(watchdog_data_mutex);
/* Release our data struct when we're detached from the i2c client *and* all
references to our watchdog device are released */
static void fschmd_release_resources(struct kref *ref)
{
struct fschmd_data *data = container_of(ref, struct fschmd_data, kref);
kfree(data);
}
/*
* Sysfs attr show / store functions
......@@ -548,7 +593,265 @@ static struct sensor_device_attribute fschmd_fan_attr[] = {
/*
* Real code
* Watchdog routines
*/
static int watchdog_set_timeout(struct fschmd_data *data, int timeout)
{
int ret, resolution;
int kind = data->kind + 1; /* 0-x array index -> 1-x module param */
/* 2 second or 60 second resolution? */
if (timeout <= 510 || kind == fscpos || kind == fscscy)
resolution = 2;
else
resolution = 60;
if (timeout < resolution || timeout > (resolution * 255))
return -EINVAL;
mutex_lock(&data->watchdog_lock);
if (!data->client) {
ret = -ENODEV;
goto leave;
}
if (resolution == 2)
data->watchdog_control &= ~FSCHMD_WDOG_CONTROL_RESOLUTION;
else
data->watchdog_control |= FSCHMD_WDOG_CONTROL_RESOLUTION;
data->watchdog_preset = DIV_ROUND_UP(timeout, resolution);
/* Write new timeout value */
i2c_smbus_write_byte_data(data->client, FSCHMD_REG_WDOG_PRESET,
data->watchdog_preset);
/* Write new control register, do not trigger! */
i2c_smbus_write_byte_data(data->client, FSCHMD_REG_WDOG_CONTROL,
data->watchdog_control & ~FSCHMD_WDOG_CONTROL_TRIGGER);
ret = data->watchdog_preset * resolution;
leave:
mutex_unlock(&data->watchdog_lock);
return ret;
}
static int watchdog_get_timeout(struct fschmd_data *data)
{
int timeout;
mutex_lock(&data->watchdog_lock);
if (data->watchdog_control & FSCHMD_WDOG_CONTROL_RESOLUTION)
timeout = data->watchdog_preset * 60;
else
timeout = data->watchdog_preset * 2;
mutex_unlock(&data->watchdog_lock);
return timeout;
}
static int watchdog_trigger(struct fschmd_data *data)
{
int ret = 0;
mutex_lock(&data->watchdog_lock);
if (!data->client) {
ret = -ENODEV;
goto leave;
}
data->watchdog_control |= FSCHMD_WDOG_CONTROL_TRIGGER;
i2c_smbus_write_byte_data(data->client, FSCHMD_REG_WDOG_CONTROL,
data->watchdog_control);
leave:
mutex_unlock(&data->watchdog_lock);
return ret;
}
static int watchdog_stop(struct fschmd_data *data)
{
int ret = 0;
mutex_lock(&data->watchdog_lock);
if (!data->client) {
ret = -ENODEV;
goto leave;
}
data->watchdog_control &= ~FSCHMD_WDOG_CONTROL_STARTED;
/* Don't store the stop flag in our watchdog control register copy, as
its a write only bit (read always returns 0) */
i2c_smbus_write_byte_data(data->client, FSCHMD_REG_WDOG_CONTROL,
data->watchdog_control | FSCHMD_WDOG_CONTROL_STOP);
leave:
mutex_unlock(&data->watchdog_lock);
return ret;
}
static int watchdog_open(struct inode *inode, struct file *filp)
{
struct fschmd_data *pos, *data = NULL;
/* We get called from drivers/char/misc.c with misc_mtx hold, and we
call misc_register() from fschmd_probe() with watchdog_data_mutex
hold, as misc_register() takes the misc_mtx lock, this is a possible
deadlock, so we use mutex_trylock here. */
if (!mutex_trylock(&watchdog_data_mutex))
return -ERESTARTSYS;
list_for_each_entry(pos, &watchdog_data_list, list) {
if (pos->watchdog_miscdev.minor == iminor(inode)) {
data = pos;
break;
}
}
/* Note we can never not have found data, so we don't check for this */
kref_get(&data->kref);
mutex_unlock(&watchdog_data_mutex);
if (test_and_set_bit(0, &data->watchdog_is_open))
return -EBUSY;
/* Start the watchdog */
watchdog_trigger(data);
filp->private_data = data;
return nonseekable_open(inode, filp);
}
static int watchdog_release(struct inode *inode, struct file *filp)
{
struct fschmd_data *data = filp->private_data;
if (data->watchdog_expect_close) {
watchdog_stop(data);
data->watchdog_expect_close = 0;
} else {
watchdog_trigger(data);
dev_crit(&data->client->dev,
"unexpected close, not stopping watchdog!\n");
}
clear_bit(0, &data->watchdog_is_open);
mutex_lock(&watchdog_data_mutex);
kref_put(&data->kref, fschmd_release_resources);
mutex_unlock(&watchdog_data_mutex);
return 0;
}
static ssize_t watchdog_write(struct file *filp, const char __user *buf,
size_t count, loff_t *offset)
{
size_t ret;
struct fschmd_data *data = filp->private_data;
if (count) {
if (!nowayout) {
size_t i;
/* Clear it in case it was set with a previous write */
data->watchdog_expect_close = 0;
for (i = 0; i != count; i++) {
char c;
if (get_user(c, buf + i))
return -EFAULT;
if (c == 'V')
data->watchdog_expect_close = 1;
}
}
ret = watchdog_trigger(data);
if (ret < 0)
return ret;
}
return count;
}
static int watchdog_ioctl(struct inode *inode, struct file *filp,
unsigned int cmd, unsigned long arg)
{
static struct watchdog_info ident = {
.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
WDIOF_CARDRESET,
.identity = "FSC watchdog"
};
int i, ret = 0;
struct fschmd_data *data = filp->private_data;
switch (cmd) {
case WDIOC_GETSUPPORT:
ident.firmware_version = data->revision;
if (!nowayout)
ident.options |= WDIOF_MAGICCLOSE;
if (copy_to_user((void __user *)arg, &ident, sizeof(ident)))
ret = -EFAULT;
break;
case WDIOC_GETSTATUS:
ret = put_user(0, (int __user *)arg);
break;
case WDIOC_GETBOOTSTATUS:
if (data->watchdog_state & FSCHMD_WDOG_STATE_CARDRESET)
ret = put_user(WDIOF_CARDRESET, (int __user *)arg);
else
ret = put_user(0, (int __user *)arg);
break;
case WDIOC_KEEPALIVE:
ret = watchdog_trigger(data);
break;
case WDIOC_GETTIMEOUT:
i = watchdog_get_timeout(data);
ret = put_user(i, (int __user *)arg);
break;
case WDIOC_SETTIMEOUT:
if (get_user(i, (int __user *)arg)) {
ret = -EFAULT;
break;
}
ret = watchdog_set_timeout(data, i);
if (ret > 0)
ret = put_user(ret, (int __user *)arg);
break;
case WDIOC_SETOPTIONS:
if (get_user(i, (int __user *)arg)) {
ret = -EFAULT;
break;
}
if (i & WDIOS_DISABLECARD)
ret = watchdog_stop(data);
else if (i & WDIOS_ENABLECARD)
ret = watchdog_trigger(data);
else
ret = -EINVAL;
break;
default:
ret = -ENOTTY;
}
return ret;
}
static struct file_operations watchdog_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.open = watchdog_open,
.release = watchdog_release,
.write = watchdog_write,
.ioctl = watchdog_ioctl,
};
/*
* Detect, register, unregister and update device functions
*/
/* DMI decode routine to read voltage scaling factors from special DMI tables,
......@@ -658,9 +961,9 @@ static int fschmd_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct fschmd_data *data;
u8 revision;
const char * const names[5] = { "Poseidon", "Hermes", "Scylla",
"Heracles", "Heimdall" };
const int watchdog_minors[] = { WATCHDOG_MINOR, 212, 213, 214, 215 };
int i, err;
enum chips kind = id->driver_data;
......@@ -670,6 +973,13 @@ static int fschmd_probe(struct i2c_client *client,
i2c_set_clientdata(client, data);
mutex_init(&data->update_lock);
mutex_init(&data->watchdog_lock);
INIT_LIST_HEAD(&data->list);
kref_init(&data->kref);
/* Store client pointer in our data struct for watchdog usage
(where the client is found through a data ptr instead of the
otherway around) */
data->client = client;
if (kind == fscpos) {
/* The Poseidon has hardwired temp limits, fill these
......@@ -690,6 +1000,17 @@ static int fschmd_probe(struct i2c_client *client,
}
}
/* Read in some never changing registers */
data->revision = i2c_smbus_read_byte_data(client, FSCHMD_REG_REVISION);
data->global_control = i2c_smbus_read_byte_data(client,
FSCHMD_REG_CONTROL);
data->watchdog_control = i2c_smbus_read_byte_data(client,
FSCHMD_REG_WDOG_CONTROL);
data->watchdog_state = i2c_smbus_read_byte_data(client,
FSCHMD_REG_WDOG_STATE);
data->watchdog_preset = i2c_smbus_read_byte_data(client,
FSCHMD_REG_WDOG_PRESET);
/* i2c kind goes from 1-5, we want from 0-4 to address arrays */
data->kind = kind - 1;
......@@ -732,9 +1053,43 @@ static int fschmd_probe(struct i2c_client *client,
goto exit_detach;
}
revision = i2c_smbus_read_byte_data(client, FSCHMD_REG_REVISION);
/* We take the data_mutex lock early so that watchdog_open() cannot
run when misc_register() has completed, but we've not yet added
our data to the watchdog_data_list (and set the default timeout) */
mutex_lock(&watchdog_data_mutex);
for (i = 0; i < ARRAY_SIZE(watchdog_minors); i++) {
/* Register our watchdog part */
snprintf(data->watchdog_name, sizeof(data->watchdog_name),
"watchdog%c", (i == 0) ? '\0' : ('0' + i));
data->watchdog_miscdev.name = data->watchdog_name;
data->watchdog_miscdev.fops = &watchdog_fops;
data->watchdog_miscdev.minor = watchdog_minors[i];
err = misc_register(&data->watchdog_miscdev);
if (err == -EBUSY)
continue;
if (err) {
data->watchdog_miscdev.minor = 0;
dev_err(&client->dev,
"Registering watchdog chardev: %d\n", err);
break;
}
list_add(&data->list, &watchdog_data_list);
watchdog_set_timeout(data, 60);
dev_info(&client->dev,
"Registered watchdog chardev major 10, minor: %d\n",
watchdog_minors[i]);
break;
}
if (i == ARRAY_SIZE(watchdog_minors)) {
data->watchdog_miscdev.minor = 0;
dev_warn(&client->dev, "Couldn't register watchdog chardev "
"(due to no free minor)\n");
}
mutex_unlock(&watchdog_data_mutex);
dev_info(&client->dev, "Detected FSC %s chip, revision: %d\n",
names[data->kind], (int) revision);
names[data->kind], (int) data->revision);
return 0;
......@@ -748,6 +1103,24 @@ static int fschmd_remove(struct i2c_client *client)
struct fschmd_data *data = i2c_get_clientdata(client);
int i;
/* Unregister the watchdog (if registered) */
if (data->watchdog_miscdev.minor) {
misc_deregister(&data->watchdog_miscdev);
if (data->watchdog_is_open) {
dev_warn(&client->dev,
"i2c client detached with watchdog open! "
"Stopping watchdog.\n");
watchdog_stop(data);
}
mutex_lock(&watchdog_data_mutex);
list_del(&data->list);
mutex_unlock(&watchdog_data_mutex);
/* Tell the watchdog code the client is gone */
mutex_lock(&data->watchdog_lock);
data->client = NULL;
mutex_unlock(&data->watchdog_lock);
}
/* Check if registered in case we're called from fschmd_detect
to cleanup after an error */
if (data->hwmon_dev)
......@@ -762,7 +1135,10 @@ static int fschmd_remove(struct i2c_client *client)
device_remove_file(&client->dev,
&fschmd_fan_attr[i].dev_attr);
kfree(data);
mutex_lock(&watchdog_data_mutex);
kref_put(&data->kref, fschmd_release_resources);
mutex_unlock(&watchdog_data_mutex);
return 0;
}
......@@ -824,17 +1200,6 @@ static struct fschmd_data *fschmd_update_device(struct device *dev)
data->volt[i] = i2c_smbus_read_byte_data(client,
FSCHMD_REG_VOLT[i]);
data->global_control = i2c_smbus_read_byte_data(client,
FSCHMD_REG_CONTROL);
/* To be implemented in the future
data->watchdog[0] = i2c_smbus_read_byte_data(client,
FSCHMD_REG_WDOG_PRESET);
data->watchdog[1] = i2c_smbus_read_byte_data(client,
FSCHMD_REG_WDOG_STATE);
data->watchdog[2] = i2c_smbus_read_byte_data(client,
FSCHMD_REG_WDOG_CONTROL); */
data->last_updated = jiffies;
data->valid = 1;
}
......
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